Adult Helmets (Men & Women)

US Size Centimeters Inches
X-Small 53 – 54 20 7/8 – 21 1/4
Small 55 – 56 21 5/8 – 22
Medium 57 – 58 22 1/2 – 22 7/8
Large 59 – 60 23 1/4 – 23 5/8
X-Large 61 – 62 24 – 24 1/2

Junior Helmets (Girls & Boys)

US Size Centimeters Inches
XX-Small 51 – 52 20 – 20 1/2
X-Small 53 – 54 20 7/8 – 21 1/4
Small 55 – 56 21 5/8 – 22
Medium 57 – 58 22 1/2 – 22 7/8